Investigation of Rapid Filling of Empty Pipes

Water mains are periodically subjected to maintenance, in which drain and refill of pipeline sections is a required practice. There is the possibility of damage to the water main during such operations, even when air relief valves and vacuum breakers are properly placed or the drain and refill are conducted slowly. Current research on this and related applications has resulted in different numerical models to simulate the rapid filling process (Liou and Hunt, 1996; Izquierdo et al. 1999) based on the assumption that a vertical interface can represent the water inflow front. Models to simulate the rapid filling of stormwater sewers have also used this assumption, as exemplified by Zhou et al. (2002). Research on the rapid filling of initially empty pipes was conducted at the National School of Engineering of Tunis (Tunisia) and the University of Michigan. This research was conducted to gain a better understanding of the filling process in closed pipes and thus try to optimize the filling operations and minimize the risk of damages. An experimental investigation was performed to characterize the inflow fron